The military commissioned a cold weather top, or "closure,"
for use on the new M-38
Jeep Jeep which went into production in 1950. The cold
weather closure, nicknamed the "arctic top," saw action during the Korean war,
and has a reputation as being the best-built aluminium top manufactured for
either military or civilian Jeeps.

In a brief article discussing this "arctic top" in West
Coast Willys, a Jeep owners' newsletter, the actual name of the top is
quoted from the Willys-Overland identifying tag: "Cab-Closure Hard Top." We
should really use that designation, because the term "arctic top" was only a
nickname for the W-O military top. The actual trade name "Arctic Top" belonged
to the civilian top made by Metro Engineering (see below.)

In
this example the closure is used on a World War II GPW which is incorrect, but
it fits perfectly. If we compare this "arctic top" with those tops manufactured
in Steyr prior to the end of World War II, there are some interesting
differences.

When the M-38 closure was designed, the Stehr door hinged to
the sloping windshield was not chosen as an adequate solution. It was possibly
too dangerous as it could crush careless fingers when swinging shut. Instead,
the standard M-38 windshield was discarded and replaced with a modified
windshield which was set in the vertical position. The arms go straight down and
bolt directly to the cowl. The reason for this change of position of the
windshield is most likely that it allows the door to open on a vertical hinge,
eliminating the dangers of the Steyr door.

In the installation instructions, the term "arctic top" is not used. This
diagram provided by Wes Knettle from the manual, shows the differences between
the hardtop windshield and the standard M-38 (or CJ-3A) windshield. The
windshield arms go straight down instead of bending forward to a pivot. The Jeep
can be driven using this windshield with the top removed (see
Mark Hallenbeck's M38, 20K JPEG) but the top does not fold down.

Full winter equipment would also include a
gas-operated heater (70K JPEG) mounted outside on the cowl, with hot air
ducted through the vent in the windshield frame (photo by Roberto Bruciamonti.)